Hondata

ok so for some reason i dunno why but maybe you guys can tell me, i setup the duty cycle to 65% with a boost cut to 16psi, sometimes she will just fly and hit boost cut and other times she will be steady at around 14-14.5 psi witch is what it should be.

or when i went on the dyno she was just all over the place 19psi drop to 12 and so on could somebody explain to me y is that and then she desides to work sometimes. coulnt get tuned on race fuel because of that.

civic hatch 98 with b16a 2gen
benson sleeved
cp 9:1
manley rods
supertech valvetrain
gt3076r
2.5inch hotside charge piping and 3" cold side
hondata 4bar map sensor
tial 44mm wastegate
tial 50mm BOV

anything else ?

using a p06 with pwm and s300 chipped by phearable.net wont hold boost

it wont hold boost and other times it does.

and im runing a MAC boost solenoid witch is the same as the hondata and AEM one, its located right in front of my exhaust and top mount manifold could that cause the boost solenoid to not work properly since it most likely gets really hot.

Heat could definately be a factor in why it is changing, but it appears you are just using a set duty cycle of 64%. If you have not actually gone through and tried different duty cycles and entered the vales in the table below you will not have the correct duty cycle for the amount of boost you want to run.

oh ive tried different values, it just seems like sometimes ill hit 14.5 psi at like 58% duty cycle just as a example, but ill try and catch more datalogging tonight ;) but you think moving the solenoid to a colder place could solve the problem ?

but for it to fluter psi like that, i dunno lol coulnt tune it on c16 since it was going to like 19psi than drop down to 12 and back up again.

What size spring are you running in that 44mm gate?

its like a 11 or 10psi. could that be it ?

Spunkster wrote:Heat could definately be a factor in why it is changing, but it appears you are just using a set duty cycle of 64%. If you have not actually gone through and tried different duty cycles and entered the vales in the table below you will not have the correct duty cycle for the amount of boost you want to run.

Can you elaborate on this a bit more?

Are you saying.. You have to run a specific Duty cycle, then whatever the PSI is.. You enter that Into the chart? and Keep going up, uptill it's all filled out?

Or.. Do you follow the chart for a precise PSI?

element wrote:its like a 11 or 10psi. could that be it ?

its possible. We see lots of surge and spike issues when pushing past the spring pressure that much. The general rule is no more than 2x the spring, or you get boost control probs.

Taken directly from the Help file:

The Pressure vs Duty Cycle table contains a lookup of pressure valves which correspond to a solenoid duty cycle. The values for this table must be set by using a fixed duty cycle (see Control Method) and noting the resulting manifold pressure. Note that different ambient conditions will result in slightly different boost pressures for the same duty cycle.

^^^ And altitude changes.

Spunkster wrote:Taken directly from the Help file:

The Pressure vs Duty Cycle table contains a lookup of pressure valves which correspond to a solenoid duty cycle. The values for this table must be set by using a fixed duty cycle (see Control Method) and noting the resulting manifold pressure. Note that different ambient conditions will result in slightly different boost pressures for the same duty cycle.

How are you supposed to accomplish this when you don't really want to boost more than 'said' amount...

So.. It's basicly a 'hit or miss' sort of thing?

Set a boost cut if you don't want to exceed a certain boost level.